// ------------------------------------------------------------------------------
// 
// Copyright (c) 2008 Swampware, Inc.
// 
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
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// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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// OTHER DEALINGS IN THE SOFTWARE.
// 
// ------------------------------------------------------------------------------
using System;

namespace Bamboo.Query.Aggregators
{
	public class SumDoubleAggregator : Aggregator
	{
		private int _index;
		private double _sum;

		public SumDoubleAggregator(int index)
		{
			this._index = index;
		}

		public override void Open()
		{
			this._sum = 0;
		}

		public override void Apply(System.Collections.IList row)
		{
			object value = row[this._index];
			if(value != null)
			{
				this._sum += System.Convert.ToDouble(row[this._index]);
			}
		}

		public override object Close()
		{
			return this._sum;
		}

	}
}
